diff --git a/Gemfile b/Gemfile
index 4e20389..1ba9975 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,7 +4,7 @@ ruby "2.5.1"
 
 gem 'rails', '~> 5.1.6'
 gem 'pg', '>= 0.18', '< 2.0'
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3'
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
 gem 'webpacker'
diff --git a/Gemfile.lock b/Gemfile.lock
index 886068d..03b4f37 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -99,7 +99,8 @@ GEM
       pry (~> 0.10)
     pry-rails (0.3.9)
       pry (>= 0.10.4)
-    puma (3.12.2)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.0.8)
     rack-proxy (0.6.5)
       rack
@@ -207,7 +208,7 @@ DEPENDENCIES
   pg (>= 0.18, < 2.0)
   pry-byebug
   pry-rails
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.6)
   rspec-rails
   sass-rails (~> 5.0)